[RFC PATCH v3 10/17] x86/resctrl: Add data structures for ABMC assignment

From: Babu Moger
Date: Thu Mar 28 2024 - 21:09:42 EST


ABMC (Bandwidth Monitoring Event Configuration) counters can be configured
by writing to L3_QOS_ABMC_CFG MSR. When ABMC is enabled, the user can
configure a counter by writing to L3_QOS_ABMC_CFG setting the CfgEn field
while specifying the Bandwidth Source, Bandwidth Types, and Counter
Identifier. Add the MSR definition and individual field definitions.

MSR L3_QOS_ABMC_CFG (C000_03FDh) definitions.

==========================================================================
Bits Mnemonic Description Access Type Reset Value
==========================================================================
63 CfgEn Configuration Enable R/W 0

62 CtrEn Counter Enable R/W 0

61:53 – Reserved MBZ 0

52:48 CtrID Counter Identifier R/W 0

47 IsCOS BwSrc field is a COS R/W 0
(not an RMID)

46:44 – Reserved MBZ 0

43:32 BwSrc Bandwidth Source R/W 0
(RMID or COS)

31:0 BwType Bandwidth types to R/W 0
track for this counter
==========================================================================

The feature details are documentd in the APM listed below [1].
[1] AMD64 Architecture Programmer's Manual Volume 2: System Programming
Publication # 24593 Revision 3.41 section 19.3.3.3 Assignable Bandwidth
Monitoring (ABMC).

Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537

---
v3: No changes.
v2: No changes.
---
arch/x86/include/asm/msr-index.h | 1 +
arch/x86/kernel/cpu/resctrl/internal.h | 23 +++++++++++++++++++++++
2 files changed, 24 insertions(+)

diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index f16ee50b1a23..ab01abfab089 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -1166,6 +1166,7 @@
#define MSR_IA32_SMBA_BW_BASE 0xc0000280
#define MSR_IA32_EVT_CFG_BASE 0xc0000400
#define MSR_IA32_L3_QOS_EXT_CFG 0xc00003ff
+#define MSR_IA32_L3_QOS_ABMC_CFG 0xc00003fd

/* MSR_IA32_VMX_MISC bits */
#define MSR_IA32_VMX_MISC_INTEL_PT (1ULL << 14)
diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index b559b3a4555e..41b06d46ea74 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -106,6 +106,9 @@ cpumask_any_housekeeping(const struct cpumask *mask, int exclude_cpu)
#define ASSIGN_TOTAL BIT(0)
#define ASSIGN_LOCAL BIT(1)

+/* Maximum assignable counters per resctrl group */
+#define MAX_ASSIGN_CNTRS 2
+
struct rdt_fs_context {
struct kernfs_fs_context kfc;
bool enable_cdpl2;
@@ -210,6 +213,7 @@ enum rdtgrp_mode {
* @crdtgrp_list: child rdtgroup node list
* @rmid: rmid for this rdtgroup
* @mon_state: Assignment state of the group
+ * @abmc_ctr_id: ABMC counterids assigned to this group
*/
struct mongroup {
struct kernfs_node *mon_data_kn;
@@ -217,6 +221,7 @@ struct mongroup {
struct list_head crdtgrp_list;
u32 rmid;
u32 mon_state;
+ u32 abmc_ctr_id[MAX_ASSIGN_CNTRS];
};

/**
@@ -566,6 +571,24 @@ union cpuid_0x10_x_edx {
unsigned int full;
};

+/*
+ * L3_QOS_ABMC_CFG MSR details. ABMC counters can be configured
+ * by writing to L3_QOS_ABMC_CFG.
+ */
+union l3_qos_abmc_cfg {
+ struct {
+ unsigned long bw_type :32,
+ bw_src :12,
+ rsvrd1 : 3,
+ is_cos : 1,
+ ctr_id : 5,
+ rsvrd : 9,
+ ctr_en : 1,
+ cfg_en : 1;
+ } split;
+ unsigned long full;
+};
+
void rdt_last_cmd_clear(void);
void rdt_last_cmd_puts(const char *s);
__printf(1, 2)
--
2.34.1